The melting of ice and snow which accumulates on the roof of structures can create severe problems in cold weather. Heat from the structure partially melts the ice and snow, and the resulting water then runs down the roof. As this water encounters cold air at the lower edge, or eaves, of the roof, it freezes and forms an ice dam. The ice dam builds as this process repeats itself and eventually grows large enough to cause water to back up under the shingles on the roof and enter the structure. This is a common problem in cold climates and numerous solutions have been proposed.
One solution is to provide heating wires in a zig-zag pattern along the lower edge of the roof. These wires only partially melt the ice and snow on the roof, and additionally, may not be mounted to the roof in a secure manner, therefore, necessitating frequent replacement or repair.
Another solution commonly used is a metal roof slide comprising panels, typically formed of aluminum, mounted on top of the roof shingles along the lower edge of the roof. The roof slide is designed to facilitate the sliding of ice and snow off the roof.
A system of roof heater shingles is shown in U.S. Pat. No. 3,691,343 to Norman. In the Norman design a row of shingles are mounted along the lower edge of the roof and are connected in series to a power source. The shingles comprise a wire disposed along a back surface of a panel in a trapezoidal pattern. A valley section is also provided for melting ice and snow in the valley of the roof. A separate row of shingles is provided for each uninterrupted section of the roof, with the separate rows connected in parallel. An indicator is provided in the main power circuit of the system. The indicator light merely provides an indication of power to the entire system. If a shingle in the Norman design fails, there is no indication of that failure and that entire row of shingles ceases to operate, thereby allowing ice and snow to build up along that entire section of the roof.
It is an object of the present invention to provide an improved roof deicing system which reduces or wholly overcomes some or all of the aforesaid difficulties inherent in prior known devices. Particular objects and advantages of the invention will be apparent to those skilled in the art, that is, those who are knowledgeable and experienced in this field of technology, in view of the following disclosure of the invention and detailed description of certain preferred embodiments.